360-FAAR (Firewall Analysis Audit and Repair) is an offline, command line, Perl firewall policy manipulation tool to filter, compare to logs, merge, translate, and output firewall commands for new policies, in Checkpoint dbedit, Cisco ASA, or ScreenOS commands. It is all contained in one file. It can read policy and logs for: Checkpoint FW1 (in odumper.csv / logexport format), Netscreen ScreenOS (in get config / syslog format), and Cisco ASA (show run / syslog format). It uses both inclusive and exclusive CIDR and text filters, permitting you to split large policies into smaller ones for virutalization at the same time as removing unused connectivity. It supports policy to log association, object translation, rulebase reordering and simplification, rule moves, and duplicate matching automatically. It allows you to seamlessly move rules to where you need them. 'print' mode creates a spreadsheet for your audit needs with one command.

ADSL4Linux is a program to install ADSL under Linux in the easiest way
possible. The install script consists of 3 easy steps and it does not require
any deep knowledge of Linux. It currently only works for MXStream by KPN in the
Netherlands.

AGT is a powerful console frontend to iptables,
supporting nearly all of the iptables extensions
(such as quota, random, MIRROR, multiport, owner,
string, MAC address, and more). All options can be
specified in a configuration file with similar
syntax to 'ipf' and 'ipfw'.

AMaViS (A Mail Virus Scanner) scans e-mail
attachments for viruses using third-party virus
scanners available for UNIX environments. It
resides on a UNIX (Linux) machine and looks
through the attached files arriving via e-mail,
generates reports when a virus is found and sets
the delivery on hold.

Actim allows you to send and retrieve files, and to call command line programs on a target machine via emails. The application can handle both synchronous and asynchronous requests with basic security features. It has both command line and graphical user interfaces. This can be useful if, for example, your home PC does not have any access to your office workstation which is behind the company firewall.

Aps is a small tool for analyzing network traffic. It prints out a great deal of information about the relevant protocols including TCP, UDP, ARP, and ICMP. It allows you to filter IP addresses, hardware addresses, ports, and specific protocols. It comes with a little GTK-GUI displaying packet counters for each protocol.

AlmostVPN is an SSH tunnel manager with a
twist. It is packaged as a Preference Panel, so
you do not have to use yet another
application to configure your tunnels. Instead,
it uses creative network configuration
techniques to provide almost VPN-like access
to remote services, so you can keep using real
IP addresses and port numbers while
accessing service on the other side of your
tunnels. It provides a simple way to mount
remote volumes, use remote printers and
faxes, access iTunes, iPhoto, and almost any
other Bonjour-based application, transfer and
execute files, and more.

Alt+Connect manages dialup connections, allowing a group of networked machines to share a single Internet connection through their server. Custom client software lets users to start or stop their internet connection, and the server (connectd) ensures that the connection remains up only while someone's using it. Features include support for multiple ISPs and links (modems or ISDN channels), connection control lists, ability to record the time a user spends online and charge him for it, and the ability to enable and disable IP forwarding as a machine starts or stops using the Internet.